Rotary machine apex seal

ABSTRACT

A rotary machine apex seal having an air directing passage connected by communicating passages in the rotor and housing to an external air pressure supply for directing air pressure to impinge upon the machine&#39;&#39;s internal peripheral wall to provide a cushion of air between the apex seal and this wall.

iied States Patent Fox, .111. 1 Sept. 11, 1973 1 ROTARY MACHINE APEXSEAL 3,655,304 4 1972 Sturmer 418/124 [75] Inventor: Ralph G. Fox, Jr.,Indianapolis, Ind. FOREIGN PATENTS OR APPLICATIONS 3 Assignee; GeneralMotors Corporation, 93,965 12/1938 Sweden.. 418/124 Detroit Mich.794,773 5/1958 Great Britain 418/79 Filed: 1972 Primary ExaminerCar1tonR. Croyle l2] 1 Appl 1 9 Assistant Examiner.lohn J. Vrablik Attorney-J.L. Carpenter and R. L. Phillips [52] U.S. Cl 418/76, 418/77, 418/79,

418/81, 418/124 [57] ABSTRAC'T I51 I Int. Cl. F01c 19/02, F040 15/00,F04c 27/00 A rotary machine apex seal having an air directing pas- [58]Field of Search 418/76, 77, 79, 81, g: nected by communicating passagesin the rotor 418/113, 123, 124, 268; 277/81 P and housing to an externalair pressure supply for di- 1 recting air pressure to impinge upon themachines in- [56] Refer s Cit d ternal peripheral wall to provide acushion of air be- UNITED STATES PATENTS tween the apex seal and thiswall. r 3,213,837 10/1965 Keylwert 418/81 5 Claims, 6 Drawing FiguresPATENTEDSUI 1 1m 3, 758,243

AIR PRESSURE SUPPLY AIR RESSURE INTERMEDIATE PRESSU Q 5 PRS L JRE ROTARYMACHINE APEX SEAL This invention relates to a rotary machine apex sealand more particularly to a rotary machine apex seal running against arotor housing on an air cushion.

In rotary machines such as rotary combustion engines, pumps, compressorsand the like, wherein a seal arrangement is provided at each rotor apexto continuously sealingly engage an internal peripheral wall to separatethe machines working chambers which rotate with the rotor, one of themajor considerations is minimization of the wear of the apex seals.There are two primary approaches to this objective, one being the choiceof peripheral wall and seal materials for compatibility and wear lifeand the other being in the area of apex seal design. Up to the presenttime the choice of materials has beensubstantially limited by thesliding friction encountered in conventional seal designs.

The rotary machine apex seal according to the present invention providesfor a wider than normal choice of materials by having a surface with asubstantial area that is opposite and remains adjacent to the rotorhousings internal peripheral wall without radial movement as the rotorrotates. An air directing passage extends through this seal surface andis connected by a passage in the rotor and a communicating passage inthe housing to an external air pressure supply. Air pressure is directedby the passage in the seal toimpinge upon the internal peripheral wallto provide a cushion of air between the seal and this wall so that theseal runs on an air cushion rather than having sliding contact with thewall.

An object of the present invention is to provide a new and improvedrotary machine apex seal. v

Another object is to provide in a rotary machine-an apex seal that runsagainst the rotor housing on a cushion of air derived from an externalair pressuresupply.

Another object is to provide in a rotary machine a rotor apex seal thathas a passage connected to deliver air from an external air pressuresupply via communieating rotor and housing passages to impinge upon therotors internal peripheral wall to provide a cushion of air between theseal and the internal peripheral wall as the rotor rotates.

Another object is to provide an apex seal for a rotary machine whereinanexternal air pressure supply is uti lized to effect an air cushionbetween each apex seal and the rotor h ousin g's internalperipheral wallto minimize seal'wear. i

These and other objectsof the present invention will become moreapparent from the following description and accompanying drawing inwhich:

FIG. 1 is a longitudinal sectional view of a rotary ma chine havingoneembodiment of the apex seals-according to the present invention.

FIG. 2 is a reduced view taken along the line 2-2 in FIG. 1.

FIG. 3 is a view taken along the line 3-3 in FIG. 1.

FIG. 4 is an enlarged view of one of the apex seals taken along the line4-4 in FIG. 1.

FIG. 5 is a view similar to FIG. 2 of a rotary machine having anotherembodiment of the apex seals accord- ,-ing to the present invention.

FIG. 6 is a view similar to FIG. 3 for the apex seals in FIG. 5. a Theapex seal according to the present invention is for use in rotarymachines including rotary combustion engines, compressors, pumps and thelike. Referring to FIGS. 1 and 2, the rotary machine may, for example,be an internal combustion engine of the Wankel type comprising astationary outer body or housing 10 having a rotor cavity 12 that isdefined by an inwardly facing internal peripheral wall 14 of a rotorhousing 15 and a pair of inwardly facing end walls 16 of end housing 17.In the Wankel engine the peripheral wall 14 is in the shape of atwo-lobed epitrochoid or a curve parallel thereto and a rotor 18 havingthe general shape of a triangle with three peripheral faces 20 ismounted within the rotor cavity 12 on an eccentric 22 of a crankshaft23, Crankshaft 23 is rotatably mounted out board of the rotor cavity insleeve bearings 24 fixed in the end housings 17 for rotation about thecenter line 25 of peripheral wall 14. An annular external toothed gear26 is integral with the inboard end of the rightcrankshaft while therotor faces 20 cooperate with the peripheral wall 14 and end walls 16 todefine three vari able volume combustion or working chambers 28. Thechambers 28 are peripherally spaced around the rotor and move with therotor within the housing as the rotor rotates about its axis 29 andplanetateswith respect to the crankshaft axis 25 to rotate crankshaft23. As shown in FIG. 2, a fuel-air inlet passage 30 whose opening andclosing is effected by motion of the rotor 18 provides for periodicadmission of fuel-air mixture to each chamber 28, a spark plug 31provides for ignition of the fuel-air mixture after compression and anexhaust passage 32 whose opening and closing is also ef fected by themotion of the rotor 18 provides for exhaust of the products ofcombustion from each chamber as the rotor rotates in the directionindicated by the arrow with each chamber undergoing intake, compression,expansion and exhaust to provide a power phase for each revolution ofthe crankshaft 23. The structure thus far described is conventional andoperates efficiently assuming there is effective sealing between theworking chambers of the engine.

.Sealing of the chambers 28 is effected by a sealing arrangementcomprising an apex seal 33 at each rotor apex and side seals 36 on eachrotor side which extend between adjacent apex seals with an intermediatecorner seal 37 near each rotor apex providin'g a sealing link betweenadjacent side and apex seals. Referring'to FIGS. 1, 2 and 3, each 'oftheapex seals'33 is mounted in an axially extending, radially outwardlyfacing.

groove 38 at each rotor apex that extends axially from one rotor side tothe other with the apex seal being re ceived at its outboard ends in anaxially extending, radially outwardly facing groove 39 in the cornerseals 37. The side seals 36 are mounted in accommodating arcuate groovesin the two sides of the rotor and extend between and' sealingly engagethe corner seals 37 which are mounted in accommodating apertures 40 inthe sides of the rotor contiguous with the opposite ends of each apexseal groove 38. Both the side seals 36 and corner seals 37 are urged bysuitable springs, not shown, to-engage the end walls 16. In addition tothis gas sealing arrangement, there is provided in each rotor side acircular oil seal 41. The oil seals 41 are mounted radially inward ofthe side seals 36 in accommodating circular grooves in the two sides oftherotor 18, these oil seal grooves being concentric with the rotor axis29. The oil seals 41 are urged by suitable springs, not shown, to engagethe rotor cavitys end walls 16.

Referring to FIGS. 1 and 4, each of the apex seals 33 according to thepresent invention has a radially inwardly facing rectangularly shapedgroove 42 that extends axially from near one end of the seal to near theother end. The base of the apex seal groove 38 is provided with acentral rectangularly shaped raised portion that extends radiallyoutward into the apex seal groove 42 a distance exceeding the maximumdistance the apex seal can move radially in groove 38 with re spect tothe rotor. The walls of the apex seal groove 42 and the raised baseportion of the rotor seal groove 38 cooperatively define an air chamber43. Longitudinally extending, circumferentially spaced slots 44 in seal33 are connected to the chamber 43 and extend radially out through theradially outwardly facing apex seal surface 46. The sea] surface 46 iscurved in cross-section as shown in FIGS. 2 and 4 to remain close over asubstantial area to the internal peripheral wall 14 without requiringradial seal movement as the rotor planetates. Furthermore, this apexseal surface area that remains close to the internal peripheral wall 14is made substantially larger than the radially inwardly facing pressureresponsive area of the apex seal exposed to chamber 43 so that when airpressure is supplied to chamber 43, the lower air pressure acting on theapex seal surface 46 that results from the pressure drop across passages44 provides a force that will counteract the radially outwardly directedforce provided by the larger pressure in chamber 43 acting on thesmaller radially outwardly facing force producing area of the apex sealto provide for the apex seal surface 46 riding on a cushion of airrather than having sliding contact with the internal peripheral surface14. Air pressure is supplied to the apex seal chambers 43 from an airpressure supply 48 that may be provided by suitable means such as aturbine compressor driven by engine exhaust gases or a pump driven bythe engine crankshaft.

Referring to FIGS. 1 and 3, connection of the air pressure supply 48 tothe chamber 43 of the apex seals 33 is provided by an axially facingcircular port 50 that is formed in one of the end walls 16 concentricwith the crankshaft axis 25 and is connected by an axially extendingpassage 52 through the associated end housing 17 to an air pressuresupply line 54 from the air pressure supply 48 so that the air pressureis thus always made available to this port. An axially leftward facingcircular port 55 is formed in the opposing side of rotor 18 between theoil seal 41 and the side seals 36 and concentric with the rotor axis 29.The rotor port'SS is radially disposed as shown in FIGS. 1 and 2 so thatduring planetation of the rotor I8 it always remains open to the housingport 50. The rotor port 55 is connected to the apex seal chambers 43 bythree equally angularly spaced, radially extending passages 58 in therotor 18 through the raised base portion of the apex seal grooves 38.During engine operation and with supply of the air pressure to the airpassages 44 in the apex seals 33 via the communicating air pressureports50 and 55 and the passages 58, air pressure is directed by thepassages 44 to impinge upon the peripheral wall 14. The differentialpressure acting on the differential pressure responsive area of eachapex seal 33 acts to separate each apex seal from the rotor housing by asmall distance such as several microns and effect a cushion or blanketof air between the apex seal and the internal peripheral walls and anair barrier between adjacent chambers as the rotor rotates instead ofsliding contact.

In the FIG. 1 4 embodiment there is thus a single air pressure supply tofloat the apex seals and as a result this pressure must be high enoughto ensure air flow out through the apex seals against the highest gaspressure experienced in the working chambers during each rotorrevolution. In the particular rotary machine the gas pressure resistingair flow out through the apex seals may be divided into three distinctlevels with the lowest occurring during that third of a rotor revolutionwhere an apex seal passes from exhaust to intake,'the next higher leveloccurring during the next third of a rotor revolution where this apexexperiences the compression phase and the highest level during the lastthird of a rotor revolution where this apex seal experiences theexpansion phase. To allow the use of lower pressures which aresufficient during certain portions of the cycle to maintain the air flowand thereby reduce air pressure supply requirements, there may beprovided several air pressure supplies of different pressures tailoredto the particular application as shown by the embodiment in FIGS. 5 and6, wherein portions similar to those shown in FIGS. 1 4 are identifiedby the same numerals only primed and new parts are identified by newnumerals. Referring to the FIGS.- 5 6 embodiment, there is provided anair pressure supply system having three separate air pressure supplies62, 64 and 66 having low, intermediate and high pressures which areconnected as schematically shown to three radially extending ports 68,and 72, respectively, in one end wall 16'. The ports 68, 70 and 72 areequally spaced 180 apart about axis 25' with the low pressure port 68intermediate the inlet port 30' and the exhaust port 32' and theintermediate and high pressure ports 70 and 72 located in that orderfrom the low pressure port 68 in the clockwise direction. The ports 68,70 and 72 are preiodically opened during each rotor revolution to threeequally angularly spaced arcuate ports 74, 76 and 78 in the opposingrotor side which are separately connected by the radially extendingdelivery passages 58' to the chambers 43 of the apex seals 33'. Thearcuate air ports 74, 76 and 78 in the rotor each extend almost ,andthus are periodically connected during substantially one-third of eachrotor revolution to the housing air ports 68, 70 and 72, respectively,as the rotor planetates. With this arrangement of porting and connectionof the particular air pressure supplies, low pressure is periodicallydelivered via housing port 68 to each'of the arcuate rotor ports 74, 76and 78 to effect air flow against the lowest gas pressures to float therespective apex seals 33 as they traverse the low engine pressure regionduring the latter portion of the exhaust phase and the beginning portionof the intake phase. Similarly, intermediate pressure is periodicallydelivered via housing port 70 to each of the arcuate rotor ports 74, 76and 78 to effect air flow against higher gas pressures to float therespective apex seals 33 as they traverse an intermediate enginepressure region during the latter portion of the compression phase andthe beginning of the expansion or power phase. Then during the remainingportion of the expansion phase and the beginning of the exhaust phase,high pressure is periodically delivered via housing port 72 to each ofthe arcuate ports 74, 76 and 78 to effect air flow against the highestgas pressures to float the respective apex seals 33 as they traverse thehigh engine pressure region during this portion of the engine cycle.Thus, as each apex seal passes through a complete cycle it is floated bysupply of low, intermediate and high pressures according to thepressures encountered in the cycle whereby there is effected floating ofthe seals with a reduction in total air pressure supply.

The above described embodiments are illustrative of the invention whichmay be modified within the scope of the appended claims.

I claim:

1 In a rotary machine a housing having an internal peripheral wall andopposite internal end walls cooperatively defining a rotor cavity, ,acrankshaft rotatably mounted in said housing, a rotor in said rotorcavity eccentrically rotatably mounted on said crankshaft, said rotorhaving a plurality of apexes that remain adjacent said internalperipheral wall when said rotor and said crankshaft rotate, said rotorfurther having peripheral faces extending between said apexes thatcooperate with said cavity walls to define a plurality of chambers thatvary in volume and move with said rotor as said rotor and saidcrankshaft rotate, apex seal means mounted on each said apex of saidrotor for continuously providing sealing between said internalperipheral wall and said rotor to sealingly separate adjacent chambersas said rotor and said crankshaft rotate, each said apex seal meanscomprising an elongated apex seal member mounted in an axially extendingradially outwardly facing groove in the respective apex portion of saidrotor for radial movement outward toward and inward from said internalperipheral wall, each said apex seal member having a radially outwardlyfacing surface with a substantial area that is opposite and remainsadjacent to said internal peripheral wall without radial seal membermovement when said rotor and said crankshaft rotate, external airpressure supply means, and air passage means in each said apex sealmember extending through said surface and operatively connected to saidexternal air pressure supply means for directing air pressure toimpinge'upon said internal peripheral wall to provide an air pressureforce which acts to separate each said apex seal member and saidinternal peripheral wall to effect a cushion of air therebetween whensaid rotor and said crankshaft rotate.

2. In a rotary machine, a housing having an internal peripheral wall andopposite internal end walls cooperatively defining a rotor "cavity, acrankshaft rotatably mounted in said housing,a'rotor in said rotorcavity eccentrically rotatably mounted on said crankshaft, said rotorhaving a plurality of apexes that remain adjacent said internalperipheral wall when said rotor and said crankshaft rotate, said rotorfurther having peripheral faces extending between said apexes thatcooperate with said cavity walls to define a plurality of chambers thatvary in volume and move with said rotor as said rotor and saidcrankshaft rotate, apex seal means mounted on each said apex of saidrotor for continuously providing sealing between said internalperipheral wall and said rotor to sealingly separate adjacent chambersas said rotor and said crankshaft rotate, each said apex seal meanscomprising an elongated apex seal member mounted in an axially extendingradially outwardly facing groove in the respective apex portion of saidrotor for radial movement outward toward and inward from said internalperipheral wall, each said apex seal member having a radially outwardlyfacing surface with a substantial area that is opposite and remainsadjacent to said internal peripheral wall without radial seal membermovement when said rotor and said crankshaft rotate, each said apex sealmember further having a surface including a radially inwardly facingsurface portion smaller than said radially outwardly facing surfaceco-operating with said rotor to provide an air chamber, external airpressure supply means, air passage means in said rotor operativelyconnecting said external air pressure supply means and each of said airchambers, and air passage means in each said apex seal member extendingthrough said outwardly facing surface and connected to therespective-air chamber for directing air pressure to impinge upon saidinternal peripheral wall to provide an air pressure force which acts toseparate each said apex seal member and said internal peripheral walland effect a cushion of air therebetween when said rotor and saidcrankshaft rotate.

3. In a rotary machine, a housing having an internal peripheral wall andopposite internal end walls cooperatively defining a rotor cavity, acrankshaft rotatably mounted in said housing, a rotor in said rotorcavity eccentrically rotatably mounted on said crankshaft, said rotorhaving a plurality of apexes that remain adjacent said internalperipheral wall when said rotor and said crankshaft rotate, said rotorfurther having peripheral faces extending between adjacent apexes thatcooperate with said cavity walls to define a plurality of chambers thatvary in volume and move with said rotor as said rotor and saidcrankshaft rotate, apex seal means mounted on each said apex of saidrotor for continuously providing sealing between said internalperipheralwall and said rotor to sealingly separate adjacent chambers assaid rotor and said crankshaft rotate, each said apex seal meanscomprising an elongated apex seal member mounted in an axially extendingradially outwardly facing groove in the respective apex portion of saidrotor for radial movement outward toward and inward from said internalperipheral wall, each said apex seal member having a radially outwardlyfacing surface with a substantial area that is opposite and remainsadjacent to said internal peripheral wall without radial seal membermovement when said rotor and said crankshaft rotate, extemalair pressuresupply means, air passage means in said housing extendingthrough one ofsaid end walls and connected to said external air pressure supply means,air passage means in said rotor operatively connected to said housingair passage meansat said one end wall, and air passage means in eachsaid apex seal member extending through saidsurface along substantiallythe length thereof and opera- .u tively connected to said rotor airpassage means for directing air pressure to" impinge upon said internalperipheral wall to providev an air pressure force which acts to separateeach said apex seal member and said internal peripheral wall and effecta cushion of air therebetween when said rotor and said crankshaftrotate.

4'. in a rotary machine, a housing having an internal crankshaft rotate,said rotor further'having peripheral faces extending between said apexesthat cooperate with said cavity walls to define a plurality of'chambersthat vary in volume and move with said rotor as said rotor and saidcrankshaft rotate, apex seal means mounted on each said apex portion ofsaid rotor for continuously providing sealing between said internalperipheral wall and said rotor to sealingly separate adjacent chambersas said rotor and said crankshaft rotate, each said apex seal meanscomprising an elongated apex seal member mounted in an axially extendingradially outwardly facing groove in the respective apex portion of saidrotor for radial movement outward toward and inward from said internalperipheral wall, said apex seal member having a radially outwardlyfacing surface with a substantial area that is opposite and remainsadjacent to said internal peripheral wall without radial seal membermovement when said rotor and said crankshaft rotate, each said apex sealmember further having a surface including a radially inwardly facingsurface portion smaller than said radially outwardly facing surfacecooperating with said rotor to provide an air chamber, a plurality ofexternal air pressure supply means having different air pressures, airpassage means in said rotor operatively sequentially connecting saidplurality of air pressure supply means to said air chambers, and airpassage means in each said apex seal member extending through saidoutwardly facing surface and connected to the respective air chamber fordirecting the different air pressures supplied thereto to impinge uponsaid internal peripheral wall to provide an air pressure force whichacts to separate each said apex seal member and said internal peripheralwall and effect a cushion of air therebetween when said rotor and saidcrankshaft rotate.

5. In a rotary machine, a housing having an internal peripheral wall andopposite internal end walls cooperatively defining a rotor cavity, acrankshaft rotatably mounted in said housing, a rotor in said rotorcavity eccentrically rotatably mounted on said crankshaft, said rotorhaving a plurality of apexes that remain adjacent said internalperipheral wall when said rotor and said crankshaft rotate, said rotorfurther having peripheral faces extending between adjacent apexes thatcooperate with said cavity walls to define a plurality of chambers thatvary in volume and move with said rotor as said rotor and saidcrankshaft rotate, apex seal means mounted on each said apex portion ofsaid rotor for continuously providing sealing between said internalperipheral wall and said rotor to sealingly separate adjacent chambersas said rotor and said crankshaft rotate, each said apex seal meanscomprising an elongated apex seal member mounted in an axially extendingradially outwardly facing groove in the respective 'apex portion of saidrotor for radial movement outward toward and inward from said internalperipheral wall, each said apex seal member having a radially outwardlyfacing surface with a substantial area that is opposite and remainsadjacent to said internal peripheral wall without radial seal membermovement when said rotor and said crankshaft rotate, a plurality ofexternal air pressure supply means having different air pressures, airpassage means in said housing connected to each of said air pressuresupply means, air passage means in said rotor for each said apex sealmeans operatively sequentially connected to said housing air passagemeans during each rotor revolution, and air passage means in each saidseal member connected to only one of said rotor air passage means fordirecting the different air pressures supplied thereto to impinge uponsaid internal peripheral wall to provide an air pressure force whichacts to separate each said apex seal member and said internal peripheralwall and effect a cushion of air therebetween when said rotor and saidcrankshaft rotate.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,758,243 Dated September 11, 1973 Inventor(s) Ralph G. FOX, Jr.

It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

Column 1, line 41, "rotor's" should read rotor housing's Signed andsealed this 4th day of February 1975.

' (SEAL) Attest:

McCOY M. GIBSON JR. Attesting Officer C. MARSHALL DANN Commissioner of.Patents

1. In a rotary machine a housing having an internal peripheral wall andopposite internal end walls cooperatively defining a rotor cavity, acrankshaft rotatably mounted in said housing, a rotor in said rotorcavity eccentrically rotatably mounted on said crankshaft, said rotorhaving a plurality of apexes that remain adjacent said internalperipheral waLl when said rotor and said crankshaft rotate, said rotorfurther having peripheral faces extending between said apexes thatcooperate with said cavity walls to define a plurality of chambers thatvary in volume and move with said rotor as said rotor and saidcrankshaft rotate, apex seal means mounted on each said apex of saidrotor for continuously providing sealing between said internalperipheral wall and said rotor to sealingly separate adjacent chambersas said rotor and said crankshaft rotate, each said apex seal meanscomprising an elongated apex seal member mounted in an axially extendingradially outwardly facing groove in the respective apex portion of saidrotor for radial movement outward toward and inward from said internalperipheral wall, each said apex seal member having a radially outwardlyfacing surface with a substantial area that is opposite and remainsadjacent to said internal peripheral wall without radial seal membermovement when said rotor and said crankshaft rotate, external airpressure supply means, and air passage means in each said apex sealmember extending through said surface and operatively connected to saidexternal air pressure supply means for directing air pressure to impingeupon said internal peripheral wall to provide an air pressure forcewhich acts to separate each said apex seal member and said internalperipheral wall to effect a cushion of air therebetween when said rotorand said crankshaft rotate.
 2. In a rotary machine, a housing having aninternal peripheral wall and opposite internal end walls cooperativelydefining a rotor cavity, a crankshaft rotatably mounted in said housing,a rotor in said rotor cavity eccentrically rotatably mounted on saidcrankshaft, said rotor having a plurality of apexes that remain adjacentsaid internal peripheral wall when said rotor and said crankshaftrotate, said rotor further having peripheral faces extending betweensaid apexes that cooperate with said cavity walls to define a pluralityof chambers that vary in volume and move with said rotor as said rotorand said crankshaft rotate, apex seal means mounted on each said apex ofsaid rotor for continuously providing sealing between said internalperipheral wall and said rotor to sealingly separate adjacent chambersas said rotor and said crankshaft rotate, each said apex seal meanscomprising an elongated apex seal member mounted in an axially extendingradially outwardly facing groove in the respective apex portion of saidrotor for radial movement outward toward and inward from said internalperipheral wall, each said apex seal member having a radially outwardlyfacing surface with a substantial area that is opposite and remainsadjacent to said internal peripheral wall without radial seal membermovement when said rotor and said crankshaft rotate, each said apex sealmember further having a surface including a radially inwardly facingsurface portion smaller than said radially outwardly facing surfaceco-operating with said rotor to provide an air chamber, external airpressure supply means, air passage means in said rotor operativelyconnecting said external air pressure supply means and each of said airchambers, and air passage means in each said apex seal member extendingthrough said outwardly facing surface and connected to the respectiveair chamber for directing air pressure to impinge upon said internalperipheral wall to provide an air pressure force which acts to separateeach said apex seal member and said internal peripheral wall and effecta cushion of air therebetween when said rotor and said crankshaftrotate.
 3. In a rotary machine, a housing having an internal peripheralwall and opposite internal end walls cooperatively defining a rotorcavity, a crankshaft rotatably mounted in said housing, a rotor in saidrotor cavity eccentrically rotatably mounted on said crankshaft, saidrotor having a plurality of apexes that remain adjacent said internalperipheral wall when said rotor and said crankshaft rotate, said rotOrfurther having peripheral faces extending between adjacent apexes thatcooperate with said cavity walls to define a plurality of chambers thatvary in volume and move with said rotor as said rotor and saidcrankshaft rotate, apex seal means mounted on each said apex of saidrotor for continuously providing sealing between said internalperipheral wall and said rotor to sealingly separate adjacent chambersas said rotor and said crankshaft rotate, each said apex seal meanscomprising an elongated apex seal member mounted in an axially extendingradially outwardly facing groove in the respective apex portion of saidrotor for radial movement outward toward and inward from said internalperipheral wall, each said apex seal member having a radially outwardlyfacing surface with a substantial area that is opposite and remainsadjacent to said internal peripheral wall without radial seal membermovement when said rotor and said crankshaft rotate, external airpressure supply means, air passage means in said housing extendingthrough one of said end walls and connected to said external airpressure supply means, air passage means in said rotor operativelyconnected to said housing air passage means at said one end wall, andair passage means in each said apex seal member extending through saidsurface along substantially the length thereof and operatively connectedto said rotor air passage means for directing air pressure to impingeupon said internal peripheral wall to provide an air pressure forcewhich acts to separate each said apex seal member and said internalperipheral wall and effect a cushion of air therebetween when said rotorand said crankshaft rotate.
 4. In a rotary machine, a housing having aninternal peripheral wall and opposite internal end walls cooperativelydefining a rotor cavity, a crankshaft rotatably mounted in said housing,a rotor in said rotor cavity eccentrically rotatably mounted on saidcrankshaft, said rotor having a plurality of apexes that remain adjacentsaid internal peripheral wall when said rotor and said crankshaftrotate, said rotor further having peripheral faces extending betweensaid apexes that cooperate with said cavity walls to define a pluralityof chambers that vary in volume and move with said rotor as said rotorand said crankshaft rotate, apex seal means mounted on each said apexportion of said rotor for continuously providing sealing between saidinternal peripheral wall and said rotor to sealingly separate adjacentchambers as said rotor and said crankshaft rotate, each said apex sealmeans comprising an elongated apex seal member mounted in an axiallyextending radially outwardly facing groove in the respective apexportion of said rotor for radial movement outward toward and inward fromsaid internal peripheral wall, said apex seal member having a radiallyoutwardly facing surface with a substantial area that is opposite andremains adjacent to said internal peripheral wall without radial sealmember movement when said rotor and said crankshaft rotate, each saidapex seal member further having a surface including a radially inwardlyfacing surface portion smaller than said radially outwardly facingsurface cooperating with said rotor to provide an air chamber, aplurality of external air pressure supply means having different airpressures, air passage means in said rotor operatively sequentiallyconnecting said plurality of air pressure supply means to said airchambers, and air passage means in each said apex seal member extendingthrough said outwardly facing surface and connected to the respectiveair chamber for directing the different air pressures supplied theretoto impinge upon said internal peripheral wall to provide an air pressureforce which acts to separate each said apex seal member and saidinternal peripheral wall and effect a cushion of air therebetween whensaid rotor and said crankshaft rotate.
 5. In a rotary machine, a housinghaving an internal peripheral wall and opposite internal end wallscooPeratively defining a rotor cavity, a crankshaft rotatably mounted insaid housing, a rotor in said rotor cavity eccentrically rotatablymounted on said crankshaft, said rotor having a plurality of apexes thatremain adjacent said internal peripheral wall when said rotor and saidcrankshaft rotate, said rotor further having peripheral faces extendingbetween adjacent apexes that cooperate with said cavity walls to definea plurality of chambers that vary in volume and move with said rotor assaid rotor and said crankshaft rotate, apex seal means mounted on eachsaid apex portion of said rotor for continuously providing sealingbetween said internal peripheral wall and said rotor to sealinglyseparate adjacent chambers as said rotor and said crankshaft rotate,each said apex seal means comprising an elongated apex seal membermounted in an axially extending radially outwardly facing groove in therespective apex portion of said rotor for radial movement outward towardand inward from said internal peripheral wall, each said apex sealmember having a radially outwardly facing surface with a substantialarea that is opposite and remains adjacent to said internal peripheralwall without radial seal member movement when said rotor and saidcrankshaft rotate, a plurality of external air pressure supply meanshaving different air pressures, air passage means in said housingconnected to each of said air pressure supply means, air passage meansin said rotor for each said apex seal means operatively sequentiallyconnected to said housing air passage means during each rotorrevolution, and air passage means in each said seal member connected toonly one of said rotor air passage means for directing the different airpressures supplied thereto to impinge upon said internal peripheral wallto provide an air pressure force which acts to separate each said apexseal member and said internal peripheral wall and effect a cushion ofair therebetween when said rotor and said crankshaft rotate.